Sadja is attending a birthday party with her friends. She is wearing a new dress that she recently bought from a boutique. She is quite self-conscious about how she's looking in the dress and is assuming that her friends are also scrutinizing her outfit. This scenario illustrates the concept of

Imaginary audience is the correct answer.

Explanation:

an informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.